Crash helmet



FIG. 1 is a front view of the crash helmet, which is the object of the present design;

FIG. 2 is a back view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a left side view thereof; and,

FIG. 5 is a top view thereof. 

The ornamental design for a crash helmet, as shown and described. 